When the fighting died down on May 2, the Army of the Potomac still held a fairly strong position. It outnumbered the Rebels, most of its men were entrenched, and the main body had lines of fortification to fall back on if needed. The Confederate army was divided, and the VI Corps back in Fredericksburg menaced the rear of the portion under the direct command of Robert E. Lee. The Second Corps of the Army of Northern Virginia had lost its commanding general, leaving J.E.B. Stuart, untested as an infantry leader, in command. Hooker’s position wasn’t as strong as it had been the previous morning, but it was not yet by any means precarious.

The Army of the Potomac was now arranged in a semicircle with both flanks anchored against a river. The III Corps under Dan Sickles, however, had formed a salient on a small hill with a clearing called Hazel Grove south of Chancellorsville. This position exposed it to attack from several sides simultaneously, but was also the most commanding artillery position for miles. With a determined force defending it from an entrenched position, and the overgrown Wilderness interfering with maneuver, it would have been difficult to seize. Several Confederates later attested that they did not believe they could have taken the position.

Fortunately for the Rebels, Hooker gave it to them. Deciding that the III Corps was in danger, he ordered Sickles back into the broad arc of the main body. This gave the Confederates two great gifts. First, they received the artillery position that E. Porter Alexander had been longing for since the previous night. Second, it vastly simplified their main task for the day, which was reuniting the two wings of the army.

With Jackson off the field, Lee wanted to be back in direct control of his forces. He ordered Stuart to attack while feeling towards the right, with the aim of linking up and consolidating the Rebel army. Stuart’s response was not tactically impressive: he simply lined up his forces and had them attack. In the close quarters of the Wilderness, more subtle approaches might not have been more effective. The strategy chosen, however, had fearsome consequences.

Things went easily for the Rebels initially. They reached Hazel Grove as Sickles was withdrawing, and captured a few guns as they attacked the tail end of his column. Alexander began posting guns in the clearing as soon as Stuart told him it was open. This was a significant moment in the battle. From this position the guns could fire on a great deal of the Federal position and could also easily reach the Chancellor house itself, which was Hooker’s headquarters.

Along the rest of the line things were not so easy. The Union army had entrenched well and inflicted terrible damage on the Confederate units attacking them. There were several close moments when it seemed the Union lines would falter, but Hooker and his other generals successfully pulled new units into position to drive off the attackers. Despite everything, Hooker’s strategy appeared to be working until Stephen Ramseur made a costly attack that drove off Charles Graham’s III Corps brigade, threatening the core of the Federal position, and its artillery.

The guns were compelled to withdraw, and Sickles sent for help. As his messenger approached Hooker at the Chancellor house, a shot from Hazel Grove hit the column Hooker was leaning against, badly concussing him shortly after 9 in the morning. Due to miscommunication and poor decisions by many people at the site, he was not relieved by Darius Couch, the ranking general on the field. Instead Hooker revived, attempted to command for a time, then collapsed again and was carried to a safer position. Couch was summoned again then, but for as much as an hour, the Army of the Potomac had no leader.

It was the worst hour possible for that to happen. Ramseur’s successful attack compelled many Union units to withdraw from their breastworks, increasing the danger to them even as they were running out of ammunition. Meade realized he was in good position to come down on the Rebel flank, but Hooker, in the throes of his concussion, was either too confused or too timid to grant Meade’s request to attack. Shortly afterward, Hooker instructed Couch to withdraw the army to a defensive line that had been set up by engineers the night before. Couch was now in command, but had no discretion to do as he saw fit. The Union troops withdrew from Chancellorsville, ending most of the day’s fighting on this front.

The casualty count on May 3 at Chancellorsville was second only to the day-long fight at Sharpsburg, but the fight at Chancellorsville only went on for about 5 hours, as opposed to the day-long drama along Antietam creek. Fighting would continue along the Rappahannock until a total withdrawal of the Union army on May 6, but for all intents and purposes Hooker had by now already lost. The decision to withdraw from Hazel Grove, granting the Confederacy a superior artillery position, ruined the defensive arrangements he had made and led directly to his concussion. That, in turn, deprived the army of leadership that could have thrown reserves into the gap that Stuart’s attack had created, and prevented Meade’s proposed flank attack, which might yet have saved the day. At a great cost, the Confederates had reunited their army.

There was more to it than just Hooker’s mistake, however. The VI Corps had been commanded very poorly by John Sedgwick. At one point due to a mistaken order, Jubal Early’s forces abandoned the defenses of Marye’s Heights. It is a testament to Sedgwick’s slowness that he could not even manage to take an unmanned position before its defenders returned. When he did conquer the hill, Sedgwick kept moving slowly and allowed his force to be stymied by, essentially, a single brigade under Cadmus Wilcox. Hooker’s continued adherence to a defensive philosophy, and appallingly slow communications between the two wings of the army, prevented the VI Corps’ activities from contributing towards any victory.

Stoneman managed to undershoot even this low bar of performance. His attack, meant to cut off Lee from Richmond and force him into either a precipitous attack or flight, failed entirely. His cavalry moved slowly and managed only cosmetic damage to the railroad . Even if they had been thorough, they struck the line in the wrong place, allowing supplies to continue reaching Lee from his depot. At the cost of blinding the Army of the Potomac, Stoneman had accomplished practically nothing. Through the poor performance of his subordinates, and his own poor decisions, Hooker’s superior strategy had failed.

Interestingly, the loss at Chancellorsville did not demoralize the Union army. Except for the XI Corps, the men believed they had fought well, and they had withdrawn from the field rather than been forced from it. Although ultimately unsuccessful, the attack at Chancellorsville demonstrated that the Army of the Potomac could outmaneuver the Rebels. The men believed their leaders had let them down in a fight they could have won.

For his part, Robert E. Lee emerged with incredible confidence, believing he commanded the finest army that had ever walked the earth. Faced with tremendous success against long odds, he thought his men invincible. It was a belief that would soon cost them, and the South, dearly.